LONDON — British Foreign Secretary Boris Johnson and two other ministers quit Monday amid a deepening crisis over Brexit that threatens to topple Prime Minister Theresa May.
Johnson's resignation came after Brexit Secretary David Davis and junior Brexit minister Steve Baker stepped down overnight, blowing apart May's claim to have finally united her squabbling government on the issue.
Johnson, a loud pro-Brexit voice within May's divided government, is unhappy with her plan to keep the U.K. and the E.U. in a free-trade zone for goods and to commit Britain to maintaining the same rules as the bloc for goods and agricultural products.
In his resignation letter shared on Twitter, Johnson complained to May that she was leading Britain into a "semi-Brexit" in which the nation has no control over large parts of its economy "still locked in the E.U. system."
The Brexit "dream is dying, suffocated by needless self-doubt," Johnson said, adding that "since I cannot in all conscience champion these proposals, I have sadly concluded that I must go."
I am proud to have served as Foreign Secretary. It is with sadness that I step down: here is my letter explaining why. pic.twitter.com/NZXzUZCjdF
Johnson's departure could embolden Brexit-supporting lawmakers in May's Conservative Party to challenge her leadership unless she backs down on the Brexit strategy she announced Friday after 12 hours of talks.
Acknowledging the extent of the crisis, her spokesman said Monday that she would fight any attempt to oust her as leader.
Jeremy Corbyn, the leader of the opposition Labour party, told the House of Commons: "The agreement took two years to reach and just two days to unravel. How can she get good deal with the E.U. when she can't even broker one within her own Cabinet?"
In his resignation letter, Davis said May’s policy is “weak” and predicted it would “lead to further demands for concessions” from the E.U.
Andrew Bridgen, another pro-Brexit lawmaker in May’s party, said her future would likely be decided at Monday’s meeting.
“What she needs to do is give up on her proposals,” he said. “There will be a robust exchange of views and my colleagues will make a decision then as to whether they will support the prime minister.”
A leadership challenge can be triggered if 15 percent of Conservative lawmakers demand it in a letter.